Public hearings about the relicensing of the Diablo Canyon nuclear plant near San Luis Obispo are pointing toward a simple conclusion — there’s no need to rush to extend the license until seismic studies are done and a new risk assessment is completed.

Until just a few months ago, Diablo Canyon was headed toward a speedy relicensing approval — with no impediments in sight to extending the roughly 2,300-megawatt power station for a couple of decades. But the earthquake-tsunami event in northeastern Japan and the resulting Fukushima Daiichi nuclear plant disaster changed everything. Japan General Counsel Jinichi Ihara underscored that point on June 8 when he described to civic leaders at an American Red Cross breakfast in Ventura County the March catastrophe as “an event beyond assumptions” and warned leaders about the need to prepare for “a multipart disaster.”

Now the nuclear industry is scrambling to recalibrate the likelihood of improbable events, including an earthquake-tsunami-power outage that could have unforeseen impacts on Diablo Canyon. Of greatest concern is the emergence of new information about earthquake faults that are much closer to the plant than originally predicted. That’s partly because new fault-detection technology has also made it possible for owner PG&E, better understand the plant’s underlying geography.

The NRC has not made up its mind on a timetable for relicensing but it suspended the process, and an advisory board has recommended an extended delay to revisit seismic risk issues. Some thoughts:

• Cost and cost sharing of retrofits will not be easy to sort out. Should Diablo Canyon need upgrades, it will take time and money to get the plant compliant. How these costs are shared between ratepayers, investors and possibly the federal government will take time to resolve.

• Lessons learned from Fukushima will take quite a while. We still do not know the precise combination of problems that led to the partial meltdown of several of the plant’s five reactors or the weaknesses in design that contributed to radiation leaks. Diablo Canyon is built on entirely different technology and it does sit far above the coast. Until lessons are fully learned, it doesn’t make sense to relicense without conditions or impose unnecessary fixes on a perfectly sound design.

The bottom line is that Diablo Canyon is an essential part of PG&E and California’s power generating system, and the plant has generally been well-run. Taking all the time that’s required to get relicensing right is in the best interest of the nuclear industry, California and most important, the citizens of San Luis Obispo and northern Santa Barbara counties who have the most at risk in case the unthinkable actually occurs.